Air suspension is a type of vehicle suspension powered by an electric or engine driven air pump or compressor. This compressor pressurizes the air, using the compressed air as a spring. Air suspension is often used in place of conventional steel springs. Many types of luxury automobiles are equipped with air suspension systems to provide a smooth, constant ride quality and in most cases a self-leveling system.
Vehicles that use air suspension today include models from Lexus®, Jeep Grand Cherokee®, General Motors vehicles, such as Cadillac®, Mercedes-Benz®, Land Rover®/Range Rover®, Audi®, Subaru®, Volkswagen®, and Lincoln®, among other types of sedans, sports cars and SUVs (sport utility vehicles).
Various types of air suspension designs can include height adjustable suspension controlled by the driver, suitable for clearing rough terrain and some systems allow the driver to choose how sporty or comfortable they want the suspension to feel. These suspension settings can also be linked to the memory seat system, which allows for the vehicle to automatically adjust the suspension to the preferences of individual drivers.
FIG. 1 is a block diagram showing the components of a conventional prior art air suspension system that has been factory installed on a vehicle. As shown, the components of an air suspension 120 for each wheel 110 includes an air spring, a solenoid valve, one at each spring, and a height sensors. The air suspension system also includes a compressor 130, a relief valve, and an air suspension controller 140. For example, the air suspension controller keeps the car at a preselected height by reading the height sensors at each wheel, and controlling the compressor, solenoid valves and relief valves to adjust the ride height for each wheel to compensate for extra cargo.
Operationally, the factory installed module reports system errors to the main vehicle computer by the bus and the main computer sends control messages to the suspension module to adjust the air suspension based on driving conditions and terrains. A status message sent by the suspension controller can contain bits representing good status or bad status for each height sensor and solenoid valve. A bad status message, such as “Check Air Suspension” can result in an advisory message to the driver being displayed as either or both a message and/or warning indicator light on the vehicle dashboard.
Status messages, such as an air bag or air strut failure can sometimes be caused by wet rot, due to old age, or moisture within the air system that damages it from the inside, or air ride suspension parts can fail because rubber dries out and punctures to the air bag which can be caused from debris on the road. With custom applications, improper installation can cause the air bags to rub against the vehicle's frame or other surrounding parts, damaging it. As time goes by, the suspension is subject to extreme wear and the sagging poor shocks and spring quality will make it difficult to properly align. This causes excessive wear to the all four tires and eventually ruins the great ride.
The factory installed air suspension repairs can be quite expensive such as up $1,500 to approximately $5,000 per air spring, which means four wheels would cost four times these amounts. The subject assignee has started to offer spring coil conversion kits that can replace the factory installed air suspension systems at a cost of up to approximately $500 to approximately $1,500 to cover all four wheels on a vehicle, which is a fraction of the costs for replacing the air suspension systems with other air suspension systems. As such, for luxury type vehicles that are in good condition and have for example, 200,000 miles or more, it would be more cost effective to use the assignees spring coils suspension kits instead of air spring suspension systems.
However, when the air suspension system are replaced with coil springs or different suspension systems, the air suspension control module reports system errors to the main vehicle computer and the bad status message results in either or both an advisory message (“Check Air Suspension System”) and/or a warning indicator light to the driver on the vehicle dashboard, letting the driver and the passengers know there is a problem with the suspension system. As such the message such as “Check Air Suspension System” and/or a warning indicator light stays on indicating that a problem exists. These dashboard warning messages and/or lights will stay on causing an annoyance to the driver, since the warning messages and/or lights cannot be easily turned off. Past attempts such as but not limited to unscrewing a dashboard bulb and/or putting tape on the dashboard display are poor “band aid” treatments that fail to stop these warning messages and/or indicator lights from being activated. Additionally, a continuous dashboard warning message and/or warning indicator light can hurt the resale of the vehicles down the road since potential buyers would be turned off by having this warning messages and warning indicators lights that stay continuously on, even though the vehicle is safe to drive.
To solve the problems associated with replacement of the air spring with coil spring, an augmentation module that communicates with the main computer is needed.